1. Field of the Invention
This invention relates to tools for automobile engine repair and servicing, and more particularly to tools designed for removing and installing the segmental valve keepers in an internal combustion engine.
2. Background
The internal combustion engine, particularly that used for automobiles, is well known in the art. The engine employs dual overhead camshafts to operate cylinder intake and exhaust valves. Each valve is held in place by a spring, a retainer and a segmental keeper, and operates reciprocally in a sleeve pressed into the engine head, called a valve guide.
The valve guide protrudes slightly above the top of the head and includes a valve seal pressed into its"" top to prevent oil leakage past the guide and into the combustion chamber. The spring which surrounds the valve stem, sits atop the head for engines with two valves per cylinder, and is held in place under compression by a retainer and a segmental valve keeper.
If it becomes necessary to repair or replace a valve spring assembly or any part of the assembly, it is first required to remove the segmental valve keeper from the particular valve. After replacement is completed, it is necessary to re-install the segmental keeper. This requires a special, hand-held tool that is designed for extracting or installing a segmental valve keeper at the top of a valve. In addition, it is necessary to have some device means of holding and firmly supporting the bottom surfaces of the valve stems during removal or installation of the valve keepers to prevent the valve stems from falling and becoming damaged. There are no known devices or equipments presently available for this clamping support function. Until now, removal and installation of valve spring assemblies has been a laborious and time-consuming process, presenting an ongoing challenge to even experienced, skilled technicians. The currently used means of supporting the valve stems, employs C-clamps, various cloths, adaptors, and all manner of jury-rigged brackets to hold the valve stems in place, often with minimal results. These minimal results include the risk of losing the segmental valve keepers, scratching the fine finish of the valves or their bores and dropping the valve stems. A specially designed device or equipment for this clamping support function is obviously needed.
Various hand-held tools have become available in the past few decades to assist in removal and re-installation of valve keepers in automotive engine heads having two valves per cylinder, with the valve springs externally located.
However, all include limitations in usage and drawbacks including possible damage to the assemblies, valves and engine.
An example of an available hand-held tool for mounting and demounting automotive valve assemblies is described in U.S. Pat. No. 3,315,399. The tool is a cylindrical member made of steel, having cavities in both ends that are shaped to fit over the top end of a valve assembly. It is operated by administering a sharp blow to the free end of the tool while it is positioned over a valve spring retainer. This is particularly suitable for engine heads with two valves per cylinder, having large valves and springs where considerable force is needed to compress a valve spring.
The potential for inflicting damage on a valve assembly is considerable in view of the method required to operate the tool, mandating a certain level of skill in its use.
However, the described tool in U.S. Pat. No. 3,315,339 and similar tools are not suited for the current, modern automobile engines because of the tool""s size and mode of operation, which is adapted for two valves per cylinder and externally accessible valve springs.
Considerable advances in engine technology have led to additional valves per cylinder to obtain a greater torque band, with a resulting better all-round performance and improved gas mileage. The new engine configuration of four recessed valves per cylinder head, thus makes use of the prior art tools impractical for the removal and installation of valve spring assemblies.
There is therefore a need for a valve keeper removal and installation tool that is specially designed for use with engines having four valves per cylinder head, in combination with a reliable, safe and inexpensive device for holding the valve stems in place while the work is being done.
There is also a need for a means of performing the task of removal and installation of the valve assemblies in a much shorter time than is presently consumed.
The invention is a combination tool system, comprising a hand-held, valve keeper remove/install tool and an engine head clamping support device that are used together for enabling the easy removal and installation of the segmental valve keepers of an internal combustion engine having cylinder heads with four valves per cylinder, and having recessed valve springs. The hand-held tool comprises a handle member and a separate piston cylinder member which is inserted in the handle end when in use. The piston cylinder includes a mechanism located in one end of the cylinder body for extracting a valve keeper, and a mechanism located in the distal end of the cylinder body for installing a valve keeper. The engine head clamping support device provides means for clamping an engine head securely and safely in place, and includes provision for a soft but firm support of the valve stems during a removal or installation procedure, avoiding the risk of causing damage to valve parts or dropping and losing parts.
A prime invention advantage is that the removal and installation of segmental valve keepers is much faster than is possible with the presently available tools and equipments.
Another advantage is that use of the invention tools does not require special technical skills to avoid possible damage to the valves.
Accordingly it is a principal object of this invention to provide a combination of tools that enable the fast, easy removal and installation of segmental valve keepers of an internal combustion engine, without causing damage to the valves or engine parts.
Another object is to provide a combination of system tools for removal and installation of valve keepers, that is inexpensive.
Further objects and advantages of the invention will be apparent from studying the following portion of the specification, the claims and the attached drawings.